In the current study, twenty lambs, aged 4 months, half male and half
female, were classified into four groups, with five in each group. The
experimental three groups of lambs were given intravenous (IV),
intramuscular (IM) and subcutaneous (SC) administrations of recombinant
ovine interferon-τ (roIFN-τ). The fourth group (normal control) of lambs
was given normal saline injections in the same way. After
administrations, blood samples were collected from the tested animals at
different time points post injection, and the serum titers of roIFN-τ
were measured using cytopathic effect (CPE) inhibition bioassay. The
results of calculating pharmacokinetic (PK) parameters using DAS
software showed that the PK characteristics of roIFN-τ through IV
injection conformed to the two-compartment open model, whose half-life
of distribution phases (T1/2α) was 0.33±0.034 h and the elimination
half-life(T1/2β) was 5.01±0.24 h. However, the PK features of IM
injection and SC injection of roIFN-τ conformed to the one compartment
open model, whose Tmax were 3.11±0.26 h and 4.83±0.43 h, respectively,
together with an elimination half life(T1/2β) of 9.11±0.76 h and 7.
43±0.58 h, and an absorption half-life (T1/2k(a)) of 1.13±0.31 h and
1.85±0.40 h, respectively. The bioavailability of roIFN-τ after IM
administration reaches 73.57%, which is greater than that of SC
administration (53.43%). These results indicate that the drug
administration effect can be preferably obtained following a single dose
IM administration of the roIFN-τ aqueous preparation. This study will
facilitate the clinical application of roIFN-τ as a potential antiviral
agent in future work.